﻿using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Security.Cryptography;
using System.Text;

namespace BPMS.Utility.Encryption
{
    public class DesEncryptor
    {
        /// <summary>
        /// 加密
        /// </summary>
        /// <param name="strSource"></param>
        /// <returns></returns>
        public static string Encrypt(string strSource)
        {
            //把字符串放到byte数组中  
            byte[] bytIn = System.Text.Encoding.Default.GetBytes(strSource);
            //建立加密对象的密钥和偏移量          
            byte[] iv = { 102, 16, 93, 156, 78, 4, 218, 32 };//定义偏移量  
            byte[] key = { 55, 103, 246, 79, 36, 99, 167, 3 };//定义密钥  
            //实例DES加密类  
            DESCryptoServiceProvider mobjCryptoService = new DESCryptoServiceProvider();
            mobjCryptoService.Key = iv;
            mobjCryptoService.IV = key;
            ICryptoTransform encrypto = mobjCryptoService.CreateEncryptor();
            //实例MemoryStream流加密密文件  
            using (System.IO.MemoryStream ms = new System.IO.MemoryStream())
            {
                using (CryptoStream cs = new CryptoStream(ms, encrypto, CryptoStreamMode.Write))
                {
                    cs.Write(bytIn, 0, bytIn.Length);
                    cs.FlushFinalBlock();
                    return System.Convert.ToBase64String(ms.ToArray());
                }
            }
        }

        /// <summary>
        /// 解密
        /// </summary>
        /// <param name="Source"></param>
        /// <returns></returns>
        public static string Decrypt(string Source)
        {
            //将解密字符串转换成字节数组  
            byte[] bytIn = System.Convert.FromBase64String(Source);
            //给出解密的密钥和偏移量，密钥和偏移量必须与加密时的密钥和偏移量相同  
            byte[] iv = { 102, 16, 93, 156, 78, 4, 218, 32 };//定义偏移量  
            byte[] key = { 55, 103, 246, 79, 36, 99, 167, 3 };//定义密钥  
            DESCryptoServiceProvider mobjCryptoService = new DESCryptoServiceProvider();
            mobjCryptoService.Key = iv;
            mobjCryptoService.IV = key;
            //实例流进行解密  
            using (System.IO.MemoryStream ms = new System.IO.MemoryStream(bytIn, 0, bytIn.Length))
            {
                ICryptoTransform encrypto = mobjCryptoService.CreateDecryptor();
                CryptoStream cs = new CryptoStream(ms, encrypto, CryptoStreamMode.Read);
                using (StreamReader strd = new StreamReader(cs, Encoding.Default))
                {
                    return strd.ReadToEnd();
                }
            }
        }
    }
}
